Just found this article via twitter, circled among mastering "engineers" (in fact Heba Kadry reposted it, the girl who mastered the latest Mars Volta album, which reaches -12.79 dB on my RG scans, and is generally mastered in a horrible fashion).

This further backs my impression that most of them don't have a single clue of what they are doing. The section about the mastering practices of Rubin and Meller are especially eye-opening to me. Masterdisk "engineers" also apparently are now out to rape the Rush back catalogue. Further down they cite phase-reverse tests to prove AAC files are different from the original (wow, REALLY?).

The good thing is, I can use this article to decide which releases to avoid in the future. But I'm really at a loss what we can do beside that. I'm really fed up with mastering "engineers" destroying music releases.

Thats round the wrong way, the article said the waveform shapes were not the relevant factor it was the person skeptical of mastered for itunes that was looking at the sum of two file with one inverted.

From the Author

Thanks for sharing the article, Kohlrabi. If you have another read of it sometime, I think you'll find it's pretty even-handed.

I get the sense that you disagree with the claims made by the mastering engineers, and not with the article itself, which tries to take a neutral stance.

Since this was piece of reportage, rather than opinion, I wanted to accurately deliver the news, present both the commentary and the criticism, and to offer some dispassionate analysis of both stances. The article tries to remain skeptical of the magnitude of the claims, but I also stand by the fact that it's unfair to dismiss them entirely without proper tests.

If you do want to read an opinion piece, you'll probably find that my own feelings about blind listening are pretty congruent with the philosophy here at Hydrogen Audio. I'm a big supporter of this site and of ABX tests in general, and I even wrote a supportive opinion piece about blind listening tests in the very same issue you cited! (You can read that here):

I will have to disagree with the extreme stance that mastering engineers are generally snake-oil salesmen (I've never had an experience that would lead me to believe that) or that Mr. Ludwig or Ms. Kadry are incompetent (I know both, and they're definitely not).

However, as a matter of personal opinion, I would agree that Rick Rubin overstates the audible differences normally found between high-res AAC files and their original WAV masters. I'd also agree that at least one of Meller's comments was probably more figurative and expressive than it was literal.

With that said, the engineers I interviewed told me that in "Mastered for iTunes", Apple also fixed an actual issue they had in the past with creating AAC files from high-resolution masters. To be fair, even Bob Ludwig agrees that 256kbps files won't necessarily sound any worse than traditional CD files - Just so long as they're created properly, and the engineer can verify there were no issues with the transfer. (He says that this is something that they're now able to do.)

The other real development appears to be that MEs can now easily and effectively hear the differences between their original master and the file that the iTunes store's proprietary encoder will create. (I'm told that, for better or worse, it's not the same encoder used in the consumer version of iTunes.)

Who knows? Even if the AACs sound identical in 95% of cases, this new ability to actually listen and check can't be a bad thing

Personally, I think the new tools are a good idea, but I'm not about to replace my music library with new "Mastered for iTunes" versions anytime soon.

I definitely appreciate the healthy dose of skepticism here on Hydrogen Audio, and would agree that people who have a service or product to sell sometimes dramatize their claims... But show me a salesman who doesn't, and I'll show you a salesman who's out of a job!

Thanks again for the share and the comments. Keep doing what you guys do!

show me a salesman who doesn't, and I'll show you a salesman who's out of a job

If that's the case, I fully support sales staff unemployment.

Haha - Fair enough.

QUOTE (saratoga @ Mar 28 2012, 22:29)

That Bob Ludwig quote where he seemingly does not understand what audio encoding is or why it might cause clipping is particularly galling from someone doing any sort of audio work. Particularly to people like me who consider the huge amount of clipping accidentally introduced by incompetent engineers to be one of the worst aspects of modern music.

Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are. From what I remember, he's come recommending that masters peak at a maximum of a full -1db below 0dbfs to reduce unintended clipping, which is an idea that was balked at by many of the mastering engineers I spoke with. Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.

QUOTE (saratoga @ Mar 28 2012, 22:29)

First everything that clown (Shepherd) says is irrelevant since you can't show that one encoding is closer to CD by subtraction. [/b] Its not that his sample size is too small its that his test is meaningless. Its not that he took a song mastered at the wrong time, its that he doesn't know what hes doing. Why are you talking about EQ when nothing he says could possibly make sense? Actually, why are you even addressing this guy aside from to say "no I'm sorry, thats not how audio works"?

What you seem to take issue with here is that I presented the most damning argument last rather than first (because that's how mounting arguments work!) Otherwise, I think we're on the same page.

Shepherd's faulty analysis was ranked high in Google and getting a ton of reads, so I felt it was only appropriate to address it in the article. Please remember that not everyone has the same level of understanding, and that a nuanced breakdown is extremely valuable to many readers.

QUOTE (greynol @ Mar 28 2012, 23:23)

I read the paper by Apple back when we first discussed it. I don't believe it said anything about "a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process," or did it?...EDIT: I read the paper again. It says nothing about additive EQ to restore frequencies that are lost during the AAC conversion process. Not a big surprise.

Correct greynol, that fact is not from the Apple paper, but from my interviews with over a half dozen of the busiest M.E.s in New York City.

They say that in practice, they use the new toolset to A/B before-and-after files, and then use additive EQ to compensate for changes in tone if they find it necessary to do so.

In theory, that's not much different than having two slightly different EQ settings so that a cassette and vinyl version sound closer.

Many of you might effectively argue that this process is subjective and open to error (true) or that the sonic differences between a 24-bit WAV and a 256kbps AAC tend to be much slighter than the differences between vinyl and cassette (also true).

QUOTE (Fandango @ Mar 28 2012, 23:14)

PS: The Dynamic Range Meter results for Ms. Kadry's latest work are worse than Frances the Mute (DR7), Amputechture (DR6) and The Bedlam in Goliath (DR6).

To be fair, I believe that's a reflection of taste rather than competence. Making a master that's less hot isn't that difficult, and it doesn't take much advanced training at all.

To argue that Kadry or any other in-demand ME don't know what they're doing misses the point. I believe they know exactly what they're doing: Making very loud masters!

Whether you dig what they're doing is an entirely different question. I just don't think it makes sense to argue about that on a "technical" level.

(Unless you we were citing some scientific double-blind tests that compare specific levels of dynamic range with perceived enjoyment. Now that would be neat! If you know of such a study, I'd be the first to read it.)

I'll admit that I haven't heard the records you've cited here, but in defense of Kadry, it's important to remember that any mastering job can be deemed "good" as long as it's what it was intended to be. We just have to judge it by the creator's criteria.

For instance: I love the sound of a lot of Dave Fridmann's work with the Flaming Lips, which is often clipped-to-death. What's important to remember is that those records aren't clipped because they're loud... they're loud because they're clipped!

That's a world of difference. That style of mixing and mastering is an aesthetic choice, and not some unintended side-effect of ignorance or accident.

The truth is that mastering engineers who get repeat clients aren't making loud records by mistake. You don't have to like their work, but I still think it's important to make a fair argument. Otherwise, we just end up sounding like dimwits who trash on studio reverbs because they don't sound like actual concert halls.

It's also useful to remember that to people younger than us, taste-based arguments against hot, bombastic masters is going to sound a whole lot like "Hey you damn kids, get off of my lawn!"

In reality, that's part of the reason the kids are into those records in the first place! Don't you remember what it's like to be young? What self-respecting American teenager wants to listen exclusively to music his parents would approve of?

In the end, I think that with the right effort, we can bring healthy dynamic range back into the mainstream. I just don't think we're going to do that by making negative or unprincipled arguments.

QUOTE (2Bdecided @ Mar 29 2012, 03:36)

It's what happens when the art-world and science/engineering-world meet head-on. ...It would probably be even worse if we only got to hear songs written by artless science types*. Good songs, badly recorded, vs bad songs perfectly recorded?

I read the paper by Apple back when we first discussed it. I don't believe it said anything about "a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process," or did it?...EDIT: I read the paper again. It says nothing about additive EQ to restore frequencies that are lost during the AAC conversion process. Not a big surprise.

Correct greynol, that fact is not from the Apple paper, but from my interviews with over a half dozen of the busiest M.E.s in New York City.

Your article states that the Mastered for iTunes process adds EQ to compensate for losses caused by the encoding process. It should say that some mastering specialists are taking a liberty that is not prescribed by the process.

QUOTE (TrustScience @ Mar 29 2012, 06:24)

They say that in practice, they use the new toolset to A/B before-and-after files, and then use additive EQ to compensate for changes in tone if they find it necessary to do so.

So that you understand, Justin, A/B is not ABX. If these specialists were to actually employ ABX then they would quickly realize that the compression process does not color the tone in the way that they imagine.

QUOTE (TrustScience @ Mar 29 2012, 06:24)

In theory, that's not much different than having two slightly different EQ settings so that a cassette and vinyl version sound closer.

It would be if the compression process actually colored the tone.

QUOTE (TrustScience @ Mar 29 2012, 06:24)

Many of you might effectively argue that this process is subjective and open to error (true)

Subjective in that some people are more capable of identifying lossy artifacts than others? Yes. Subjective in that expectation bias cannot be circumvented? No.

QUOTE (TrustScience @ Mar 29 2012, 06:24)

that the sonic differences between a 24-bit WAV and a 256kbps AAC tend to be much slighter than the differences between vinyl and cassette (also true).

Yes, but the type of audible lossy artifacts cannot be corrected through pre-equalization. To think otherwise is foolhardy.

Your article states that the Mastered for iTunes process adds EQ to compensate for losses caused by the encoding process. It should say that some mastering specialists are taking a liberty that is not prescribed by the process.

As a matter of practice, the engineers I spoke to employ the judicious use of EQ as part of the process. You're entitled to your argument, although I feel it's a semantic one. I still think the way it was expressed in the article gives the clearest picture of what engineers are actually doing. Of course, you don't have to agree!

QUOTE (greynol @ Mar 29 2012, 09:22)

So that you understand, Justin, A/B is not ABX. If these specialists were to actually employ ABX then they would quickly realize that the compression process does not color the tone in the way that they imagine.

I'm aware that A/B and ABX are different, and I believe any credible mastering engineer would be as well. The M.E.s I spoke to are arguing that faults in the encoding process have resulted in audible tonal differences in the resulting files in many cases. Whether you believe that claim is another story.

In theory, that's not much different than having two slightly different EQ settings so that a cassette and vinyl version sound closer.

It would be if the compression process actually colored the tone.

See above.

QUOTE (greynol @ Mar 29 2012, 09:22)

QUOTE (TrustScience @ Mar 29 2012, 06:24)

Many of you might effectively argue that this process is subjective and open to error (true)

Subjective in that some people are more capable of identifying lossy artifacts than others? Yes. Subjective in that expectation bias cannot be circumvented? No.

Agreed.

QUOTE (greynol @ Mar 29 2012, 09:22)

QUOTE (TrustScience @ Mar 29 2012, 06:24)

that the sonic differences between a 24-bit WAV and a 256kbps AAC tend to be much slighter than the differences between vinyl and cassette (also true).

Yes, but the type of audible lossy artifacts cannot be corrected through pre-equalization. To think otherwise is foolhardy.

Again, the mastering engineers are claiming that there were tonal differences between the resulting AACs and the 24-bit source file that are separate from what we consider expected lossy artifacts.

They also claimed that creating a different master for the encoder was able to lessen the tonal differences between files, and have stated that the iTunes Store's encoding process has been improved as part of "Mastered for iTunes."

Again, I have no way to prove or disprove these claims. I am only able to present them as consistent statements, and to allow room for skepticism, and suggest further reading to give fuller context. To take a different stance would have been dishonest and biased. The rest is for you guys to test and decide! If you come up with a scientific and newsworthy conclusion, then I can always report on that too.

As a matter of practice, the engineers I spoke to employ the judicious use of EQ as part of the process. You're entitled to your argument, although I feel it's a semantic one.

Your negligence is appalling! You are clearly misleading people into believing that judicious use of EQ is part of Apple's process. It is not.

QUOTE (TrustScience @ Mar 29 2012, 09:32)

I'm sorry greynol, but I think you're getting confused about Ludwig's point here. He suggests that lowering the peak level reduces the number of additional clipping errors introduced by the AAC encoder. According to his argument, and the Apple whitepaper, this is a separate issue from aggressive use of dynamic range compression.

Once again, I think you should be concerned with your communication. It was about Saratoga's point, not your non sequitur reply.

QUOTE (TrustScience @ Mar 29 2012, 09:32)

Of course, if you honestly think it's a neat video that adds something new to the conversation, I'd love to check it out!

I do.

QUOTE (TrustScience @ Mar 29 2012, 09:32)

I think it should be clear by now that there may be better uses of your time.

This is disappointing as you don't really inspire much confidence if you think compression and clipping are the same thing.